1. Field of the Invention
The present invention relates to an image providing apparatus for allowing an observer to observe images.
2. Description of Related Art
Heretofore disclosed is an image providing apparatus which allows an observer to observe an image by a Maxwellian view by focusing image light obtained by modulation with a spatial-light modulation element, on the center of a pupil of the observer. FIG. 12A and FIG. 12B show a state of an observer A wearing a conventional image providing apparatus 100.
As disclosed in Japanese Patent Application Laid-open Publication No. 2005-55560, an optical housing 101 is connected to a head gear 102 by use of a ball joint 103. The positions of the optical housing 101 and the head gear 102 can be changed relative to each other by use of the ball joint 103. In this image providing apparatus, as shown in FIG. 13A and FIG. 13B, it is easy to move the optical axis of the optical housing 101 vertically and horizontally with respect to the center line of a pupil of an observer A, to move the optical housing 101 closer to, or away from an eyeball of the observer A (adjustment for a length of an eye relief), and to tilt (to turn) the optical housing 101.
However, in the case of the conventional image providing apparatus, the central position of the optical axis of the optical housing 101 is displaced vertically when the length of the eye relief is adjusted. For example, when the optical housing 101 is moved closer to the eye of the observer A as shown in FIG. 12B, the central position of the optical axis of the optical housing is displaced upward. In this case, it is possible to align the center of the optical axis with the center of the pupil of the observer A by shifting a nose pad (not shown) of the head gear 102 upward with respect to the head gear 102 and thereby displacing the optical housing 101 downward. However, it is troublesome to adjust the nose pad each time.